A situation is known, for example, in which a lighting device that is used in the interior of a vehicle is attached with respect to a curved surface of a door lining. In this case, frequently, the casing that constitutes the lighting device is not of a shape that corresponds to the curved surface of the door lining, and the lighting device tends to be attached unstably with respect to the door lining.
In Japanese Patent No. 4933240, a technical concept is disclosed in which a lighting device is attached stably with respect to the curved surface of a door lining, by fastening the lighting device, which has a substantially rectangular tubular housing, to the door lining using screw members.